Placebos effect revealed in calmed brain cells

Detailed scans of brain cells in Parkinson's disease patients have revealed the action of the placebo effect on an unprecedented scale.

"It's the first time we've seen it at the single neuron level," says Fabrizio Benedetti, head of the team which conducted the experiments at the University of Turin Medical School in Italy.

When the patients in the study received a simple salt solution, their neurons responded in just the same way as when they had earlier received a drug which eased their symptoms.

"The research provides further evidence for a physiological underpinning for the placebo effect," says Jon Stoessl, at the University of British Columbia in Vancouver, Canada. His team demonstrated in 2001 that placebos can relieve symptoms by raising brain levels of dopamine, a beneficial neurotransmitter.

"We suggest that the changes we ourselves observed are also induced by release of dopamine," says Benedetti.